Tensioning device



Dec. 16, 1941. Y C), Q NELSON n 2,266,437

TENSIONING .DEVICE Filed June 28, 1940 F/6./- Y *Kiga agua@ A WTORNE'YvPatented Dec. 16, 1941 e i f UNITED STATES PATENT 'OFFICE ytranslizrsz:,'EVICE` y Western Electric Company, Incorporated, New York,N. Y., a corporationof New York Application June-'28, 1940, 342,873 1oclaims. (creia- 75) This invention relates to a tensioning device, ingtension created'by the drawing of the mateand more particularly to atensioning device for rial from Athe supply, will equal aconstanttenmaterial drawn from Aa supply. sion. The support vII in thepresentinstance is The drawing of material from a rotatable in theformofaspindle to support a reel I1, the supply, for example, from a supplyreel'mounted 5, latterfcarrying the supply I2 of material I5, and forrotation by the material being removed thereremovably fixed to thesupport or spindle by from, creates a certainamount of tension on thesuitable :means I9. The support .II is rotatably material vwhich in manyinstances is not summounted bythe aid of one or more bearings I8, cientand in all instances is not constant. This only one of which V4is shownin the 'present inexisting tension varies with variations in the stance,upon a shaft 120. AThe shaft 2|) may be thickness of the material on thereel, the tension fof a machine used in the handling of materials,increasing as the lever arm, that is, the radius for example, a taping,machine in which a reel of the material, decreases, requiring anincreasor supply of v`material is moved in av circuitous ing force torotate the reel. Therefore, to create path `around a forwardly moving VstrandY to a constant tension on a material drawn from a spirally wrapthe materialen the strand.

rotatable supply, the force required for the addi- The spring I4 isdisposed upon a vlshaft 22, one tional tension must vary with thevariations in end of which extends into .-a supporting bracket theexisting tension, but in reverse `Yorder. 23, and is fixed thereto. Thebrake member I0,

An object of the invention is to provide a tenhaving an outer portioncurvedA to conform to sioning device particularly for material drawn theannular `engaging portion of the support II from a rotatable supply andwhich is` simplein `and provided with a brake shoe 25, .extendsupstructure-and highly eiicient in creating a conwardly and isprovidedwith an integral collar stant tension on the material. f portion 26which is disposed concentric vwith the With this and other objects inview, the invenshaftand is free to rotate thereon. An aperture tioncomprises a tensioning device for Vmaterial 21 in the collar portion 26receives oneAend-of the drawn from a rotatable supply whichdevice'inspring I4, so that 4 a portion of the force of the cludes a.brake member urged into `engagement spring may urge the b rake shoe 25of the brake with a support for the supply and a follower member Il)into intimate engagement with the urged into engagement with thesupplyVby a comsupport II. l, Y -mnn force `variable by relative positioningof the 30 The follower I3 is inthe form of anarm, supmemberrand followerto create, on the material, porting roller 30 et its lowerend. whichroller a, desired tension which, when added to en existengages thesurface of the supply I2 and follows` ing varying tension eredi-,ed bythe drawing of the decreasing lever arm or `radius of the supthematerial from the supply, will equalv a conply during the removal of thematerial Iitherelstent tension. from. The roller 3.0 issupported byroller bearf Othervobjects and advantages will be apparent ings 01 otherSuitable antifliction means 32, S0 from the fonowing detaileddescription lwhen that the tensioning means will 11e in. and be detakenin lconjunction with the accompanying k.termined by the force of.y thevSpring I4. The` drawing, wherein upper end of the follower I3 is in theform of a Fig. 1 is aside elevational view of the appa- 40 bearingPortion 33. 'disposed concentric with the ratus, portions thereof beingshown in section, shaft 22, free to rotate thereon and controlled and YY Y by the spring Il.Oneface of the bearing por- Fig. 2 is an endelevational view of thestruction ,33 1S Provided with teeth 3l which areture shown in 15'1g,v 1, pertions thereof being formed to mesh withteeth 35 of a tension varybroken away, K ing collar V38, the latterbeing disposed concentric Referring-now to the drawing, thepresentemywith the shaft 22 for rotation thereon and havbodiment of theinvention includes ingeneral a ing an aperture 31 therein for'receivinthe other brake member. I0 urged int'o engagement with a end 0f thespring. Apertures 3B are formed at support; ger a, supply l2 of materialand e, spaced positionsin the collar. and extend'radifouower n urgedinto engagement with the sup- 0 ally through the outer surface thereofto receive ply by Va common force, such .as a spring i4, -a suitabletool (not shown) to cause relative Nrwhich is variable by relativepositioning of the vlrivelnellf the 0011er and the :follower I3 to brakemember I0 and follower- I3 to create on vary the force of the spring Il.4

. material Il drawn from the supply I2, a vdesired The other yface ofthebearing portion 3l of the V.tension which when addedto the existingvary'- 55 ,'follower I3 has anotch V40 positioned to receive a lug 4I ofa holding member 42, the latter being mounted upon the shaft 22 andprovided with a key 43 projecting into an elongate recess 44 in theshaft to allow axial movement of the holding member yet prevent rotationthereof. A helical spring 46 disposed concentric with the shaft 22between the holding member 42 and a collar 41, the latter fixed to theshaft 22, urges the holding member 42 to the left (Fig. 1) to cause thelug 4| to press against the surface of the .bearing portion 33 and enterthe notch 40 when the follower is moved a sufficient distance to presentthe notch to the lug. Y

During the operation of the apparatus, it will be understood that,without the added force of the brake member I0 on the support Il tocause tension on the material I5, a certain amount of tension on thematerial will exist. This tension, without the aid of the brake, may bedetermined by the force necessary to rotate the supply, namely thematerial on the reel, and the support II. Naturally, the force requiredto rotate the reel and its support increases as the lever arm decreasesduring the removal of the material from the supply, and as the requiredforce increases the tension'on the material increases, assuming thatthe' material is withdrawn at a constant speed. In order lthat thematerial mayl be handled satisfactorily, for example, in order that thematerial may be wrapped uniformly on a strand,` it is important that thetension on the material be constant and in most instances this tensionrequired is greater than that created merely by the drawing of thematerial from the supply. In the present embodiment the force for theadded tension lies in the spring I4 and its effect on the brake memberI0. This force may be determined by suitable means (not shown) and theforce may be varied by varying the relative positions of the followerand brake member, considering, for example, that the tension varyingcollar 36 is a variable portion of the follower. The teeth 34 and 35 areequally spaced and may represent indications of the force ofV the springI4. If desired, pointers, such as arrows, may be disposed on or formedin the bearing portion 33 and the collar 36 to indicate, through the aidof the teeth, the variations from a definite force.

Let it be assumed, for example, that the device as shown is set tocreate the required tension on materalof a definite size. At thebeginning of the withdrawal of the material from a full supply, theforce of the spring, transferred to the support II by the brake memberI0, is at its maximum, the total force of the spring being dividedbetween the follower and the brake member.V As the -material iswithdrawn from the supply layer by layer, the roller 30 moves inwardlytoward the axis of rotation ofthe supply, decreasing gradually the forceof the spring on the brake member to decrease the effective force on thesupport correspondingly to the increase in force necessary for thematerial to rotate the reel resulting in the combination of two forces,one decreasing while the other correspondingly increases to maintain aconstant force and, therefore, a constant tension on the material.

When the reel is empty the follower may be moved counter-clockwise aboutthe shaft 22 until the notch 40 receives the lug 4I, the latter holdingthe follower in the dotted linel Position shown in Fig, 2, so that theempty reel may beA the holding member 42 to the right against the forceof the spring 46, removing the lug 4IV from the notch 40, and allow thefollower I3 to be moved by the spring I4 until the roller 30 rests uponthe surface of the new supply of material. In this manner the adjustmentof the spring I4 is maintained and the material from the new supply maybe withdrawn under the same tension without further adjustment of thedevice.

the follower into engagement with the collar 36.

The follower may be moved longitudinally of the shaft 22 to disengagethe teeth 34 thereof from the teeth 35 of the collar, to decrease thetension or force of the spring I4 if desired.

It will, therefore, be observed that the brake member I0 may apply avarying force to the support II controlled by the decreasing radius ofthe supply through the follower I3, to cause a decreasing tension on thematerial as the existing tension, caused by the added force required torotate the supply, increases, creating -a combined constant tension onthe material.

The embodiment of the invention herein disclosed is merelyillustrativeand may be modied and departed from in many ways without departing fromthe spirit and scope of the invention as pointed out in and limitedsolely by the appended claims.

What is claimed is:

1. A tensioning device for'material drawn from a supply comprising arotatable support for a supply of material, a shaft, a brake arm mountedcn the shaft for pivotal movement about the axis thereof and intoengagement with the support, a spring disposed on the shaft to supply aforce urging the brake arm against the support to create a tension onthe material drawn from the supply, and a follower pivotally mounted onthe shaft and urged about the axis thereof by the spring to follow thesupply while decreasing in size to decrease the force of the spring.

2. A tensioning device for material drawn from a supply comprising arotatable support for a supply of material, a shaft, a brake arm mountedon the shaft for pivotal movement about' the axis thereof and intoengagement with the support, a spring disposed on the shaft to supply aforce urging the brake arm against the support to create a tension onthe material drawn from the supply, a follower pivotally mounted 'on theshaft and urged about the axis thereof by the spring to follow thesupply while decreasing in size to decrease the force of the spring. andmeans movable on the shaft relative to the follower to vary the force ofthe spring.

3. A tensioning device for material drawn from a supply comprising arotatable support for va. supply of material, a shaft, aA brake armmounted on the shaft for pivotal movement about the axis thereof andinto engagement with the support, a spring disposed en the shaft tosupply a force urgingV the brake arm against the support to create atension on the material drawn from the supply, a follower pivotallymounted on the shaft and urged about the axis thereof by the spring tofollow'the supply while decreasing in sizel to decrease the force of thespring, and a member interengaging the follower to vary the force of thespring.l Y

4. A tensioning device for material drawn fram a supply comprising arotatable support for a supply of material, a shaft, a brake arm mountedon the shaft for pivotal movement about -the by the spring to follow thesupply while decreasing in size to decrease the force of the fil axisthereof and into engagement with the supf port, a spring disposed on theshaft to supply a force urging the brake arm against the support ,tocreate a tensionk on the material drawn from the supply, and a followerpivotally mounted on the shaft and urged about the axis thereof by thespring to follow the supply while decreasing in size to decrease theforce ofthe spring, one portion ofthe follower movable relative toanother to vary the force of the spring.

I port to create a tension on thefmaterial drawn 5. A tensioning devicefor material drawn from a supply comprising a rotatablel support for asupply of material, a shaft, a brake arm mounted on the shaft forpivotal movement about the axis thereof and into engagement with thesupport, a spring disposed on the shaft to supply a. force urging thebrake arm against the support to create av tension on the material drawnfrom the supply, a follower pivotally mounted on -the shaft and urgedabout the axis thereof by the spring to follow the supply whiledecreasing in size to decrease the force of the spring, means to varythe force of the spring, and means to'v indicate the variation in theforce of the spring.

6. A tensioning device for material drawn from a supply comprisingarotatable support for a supply of material, a shaft, a brake arm mountedon the shaft for pivotal movement about the axis thereof and intoengagement with the support, a spring disposed on the shaft to supply afrom they supply, a follower pivotally mounted on the shaft and urgedabout the axis thereof by the spring to follow the supply Whiledecreasing in size to decrease the force of the spring, and a holdingmember positioned tointerengage the follower to hold the follower in aposition away from the supply when the follower is moved into theposition.

9. A tensioning device for material drawn from a supply comprising asupport, fora supply of material, rotated by the withdrawal of thematerial under an increasing existing tension varying with thedecreasing radii of the supply, a shaft, a brake arm mounted on theshaft fork ypivotal movement about the axis thereof and into engagementwith the support, a spring disposed on the shaft to supply a forceurging the brake arm against the support to create an added tension onthe material, and a follower movable on the shaft with the decreasingradii to cause variation in the force of the spring-to cause the `vadded tension to decrease. as the existing tension increases resultingin a constant tension on force urging the brake arm against the supportto create a tension on the material drawn from the supply, a follower:pivotally mounted on the shaft and urged about the axis thereof by thespring to follow the supply while decreasing in size to decrease theforce of the spring, and means to hold the follower away from the`support for the positioning of a supply of material on the support.

7. A tensioning device for material drawn from a supply comprising -arotatable support for a supply of material, a shaft, a brake arm mountedon the shaft lfor pivotal movement about the axis thereof and intoengagement with the support, a spring disposed on the shaft to supply aforce urging the brake arm against the support to create a tension onthe material drawn from the supply, a. follower pivotally mounted on theshaft and urged about .the axis thereof the material.

10. A tensioning device for material drawn from a supply comprising asupport, for a supply of material, rotated by the` withdrawal of thematerial under an increasing existing tension varying with decreasingradii of the supply, a shaft, a brake arm mounted on the shaft forpivotal movement about the axis thereof and into engagement with thesupport, aspring disposed on the shaft to supply a force urging theOSCAR G. NELSON.

